Example showing Pass by Value and Pass by Reference

This is a very simple example of Pass by value and pass by reference. I have shown both the simple type and structures in the same example.

//Program tested on Microsoft Visual Studio 2008 - Zahid Ghadialy
//Example showing pass by value and pass by reference

#include<iostream>

using namespace std;

//Pass by value
void func1(int num)
{
  num++;
}

//Pass by reference
void func2(int &num)
{
  num++;
}

typedef struct x
{
  int a;
  int *b;
}X ;

//Pass by value, pointer still incremented in b
void newFunc1(X xyz)
{
  xyz.a++;
  (*xyz.b)++;
}

//Pass by reference, both variables incremented
void newFunc2(X &xyz)
{
  xyz.a++;
  (*xyz.b)++;
}

int main()
{
  int someNum = 3;
  cout<<"\n1. someNum = "<<someNum<<endl;
  func1(someNum);
  cout<<"\n2. someNum = "<<someNum<<endl;
  func2(someNum);
  cout<<"\n3. someNum = "<<someNum<<endl;

  cout<<"\n\nTrying this on structures"<<endl;
  X someX;
  someX.a = 13;
  int number = 50;
  someX.b = &number;
  cout<<"\n1. someX.a = "<<someX.a<<"      someX.b = "<<*someX.b<<endl;
  newFunc1(someX);
  cout<<"\n2. someX.a = "<<someX.a<<"      someX.b = "<<*someX.b<<endl;
  newFunc2(someX);
  cout<<"\n3. someX.a = "<<someX.a<<"      someX.b = "<<*someX.b<<endl;
  cout<<endl;
  return 0;
}

The output is as follows: